The present invention relates to a shell structure for ski boots.
The problem of achieving an optimum securing of the foot inside the boot, while simultaneously maintaining an optimum quality standard as regards the skier's comfort, is currently strongly felt in the field.
Many devices and solutions are in fact currently known which are intended to obtain a good securing of the foot and to maintain an optimum condition of comfort thereof.
For this purpose, German patent, No. 2031751 filed on 26 June 1970, discloses a shell structure in which the region arranged at the upper portion of the metatarsal region and on the foot instep is open and can be closed by means of an adapted flap which has levers for securing it to the shell.
Said shell furthermore has, at the upper malleolar region, adapted notches to allow a deformation of the upper quarter with respect to the shell.
This known kind of boot, however, also has disadvantages: the foot is in fact secured by exerting a pressure which is approximately perpendicular to the metatarsal region of the foot, and this is not anatomically correct, since the force exerted to achieve said securing is localized in small areas; this undoubtedly creates discomfort and irritation on the metatarsal region.
U.S. Pat. No. 4,078,322 filed on 4, Aug. 1976, discloses a boot which has a longitudinal elongated slot covered by means of a transverse band-like element.
In this case, too, it can be seen that the foot securing action occurs along a direction which is approximately perpendicular to the metatarsal region, the lateral portions of the shell adjacent to the longitudinal elongated slot being rigid.
The same Applicant also filed on 13 Jan. 1986 an Italian application, no. 19063 A/86, disclosing a front-entry ski boot in which the foot securing device comprises a band-like element which is fixed at one end to the inner lower region of the shell in the region of the foot's plantar arch and extends transversely to the foot substantially at the foot's instep region.
However said device, too, has disadvantages: empty regions between the foot and the shell are created, reducing sensitivity on the skis; the foot, though embraced, can furthermore oscillate inside the boot.